PB2370: EXTRANODAL NATURAL KILLER (NK)/T-CELL LYMPHOMA, NASAL-TYPE: ABOUT 11 CASES
Authors: Yossra Aghoutane, Soukaina Haidouri, Maha EL Amani, Fatima Zahra Lbarrah, Othman Doghmi, Houda Masrar, Naoufal Benlachgar, Hajar Khibri, Wafa Ammouri, Mouna Maamar, Hicham Harmouch, Zoubida Tazi Mezalek
Journal: HemaSphere (2023)

Topic: 19. Aggressive Non-Hodgkin lymphoma - Clinical Background: Extranodal natural killer (NK)/T-cell lymphoma, Nasal-type (ENKL) is a rare but aggressive form of non-Hodgkin’s lymphoma characterized by an association with Epstein-Barr virus (EBV), and disfiguring clinical presentations. There is no standard of care for the treatment of ENKL, chemotherapy and/or radiotherappy are used for all patients able to undergo therapy, but even with treatment, mortality rates are still high. Aims: Describe the epidemiological, clinical and evolutionary characteristics of patients diagnosed with Nasal-type Extranodal NK/T-cell lymphoma (ENKL) treated in our center and report the diagnostic and therapeutic difficulties encountered in their management. Methods: We conducted a descriptive retrospective study of 11 patients diagnosed with ENKL and treated in the department of clinical hematology at Ibn Sina University Hospital Center in Rabat/Morocco, between 2013 and 2022. Results: 11 patients diagnosed with ENKL were included. Median age was 41 years with a sex ratio M/F of 10 [10 males - 1 female]. The median time to first consultation was 4 months. The most frequent symptoms were nasal obstruction [n=6], followed by odynophagia [n=3], rhinorrhea [n=2], epistaxis [n=2], nasal mass [n=2] and fungating skin lesion [n=1]. The most frequently involved site was the sinonasal tract [n=8], followed by larynx [n=1], tonsil [n=1], and skin [n=1]. The diagnosis was confirmed by histopathological analysis of biopsy specimens and immunohistochemistry. The disease was localized in 81% of the cases [n=9]. The Ann Arbor classification of our patients was as follows: stage IIE in 6 patients, stage I in 2 patients, stage IV in 2 patients and stage IE in 1 patient. The Epstein-Barr virus (EBV) antibody test and the quantification of circulating virus DNA was performed in only 3 patients; it was positive in all 3 patients. Ten of our patients received chemotherapy according to the AspaMetDex regimen (L-asparaginase with methotrexate and dexamethasone), and it was switched to DeVIC regimen (Dexamethasone, etoposide, ifosfamide and carboplatin) in one patient due to drug-induced acute pancreatitis (grade E). One patient was treated with DeVIC regimen as a first-line therapy. Five of our patients were treated with radiotherapy after chemotherapy. Among our patients, 3 were in complete remission (CR) after first-line therapy and 2 patients were in CR after second-line therapy according to ICE regimen (ifosfamide, carboplatin and etoposide). Six patients were considered to be in therapeutic failure and one death related to drug toxicity was noted. The median follow-up of our patients was 8 months [3,5 - 11] and the median of overall survival was 9 months [4 - 13 months]. At the time of this report, 63% of our patients [n=7] had died. Summary/Conclusion: Our experience highlights the importance of combining chemotherapy and radiotherapy to improve the overall survival of patients with localized ENKL. However, the prognosis of this disease remains poor and its evolution is difficult to predict, especially in the absence of the patient’s immune status towards EBV and the viral load monitoring. Keywords: NK-T cells, Non-Hodgkin’s lymphoma, Extranodal lymphoma